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John Wiegley: Putting Lenses to Work

Bay Area Haskell · 12.6K views · 2017-04-22 · 47:19

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Overview

John Wiegley's BayHac 2017 talk walks through Haskell lenses by example, showing many practical uses beyond simple record access. It is aimed at people who want to become productive with the lens library.

On Hacker News

HN recommends it as the fastest way to learn lenses by example, with far-out examples later on.

Recommended by 4 HN people across 4 months · HN mentions 2020–2024

Topics

Functional programming
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haskelllensbayhac

What people said

turboponyy · 2024-07 · Strong recommendation

As with anything Haskell, one could simply reply with "here's the formal definition." But in easily digestible terms, it's a way to narrow your view over a collection to a subset that satisfies some property, and perhaps perform some operations on that subset. This video presentation (with a very humorous audience dynamic, might I add) serves as a great introduction by example: [VIDEO]

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platz · 2020-06 · Strong recommendation

and you can learn enough lens to be productive in 1 hours with this talk without reading docs at all. You can skip the theory and go straight to usage: [VIDEO]

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lgas · 2022-11 · Recommendation

Definitely agree on lenses being one of the more mind blowing things I've encountered and eventually grokked in programming. I would also recommend [VIDEO] as a good video on lenses in part because the latter portion has some pretty far-out examples of that deep well you mentioned.

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Sources

Video by Bay Area Haskell, played through YouTube.

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